Glossary

By Ed Dalton

Here are some terms and acronyms that you might encounter while reading computer listings on eBay UK:

AppleTalk : A simple network used to connect Apple computers with printers or with each other.

Baud : The speed of a modem - same as bits per second.

Bit : One unit of data. An individual bit can have a value of 0 or 1.

Byte : A byte of data is 8 bits.

Cache : A small memory that can be accessed faster than a computer's main memory. It is used to improve a computer's performance by temporarily holding (caching) recently accessed data.

CD-ROM : (Compact Disk Read Only Memory): A non-volatile disk storage common on virtually all home and office computers.

Centronics Interface : The parallel port interface on a PC. It is typically used to connect a printer, or an external removable storage device.

DIMM : (Dual Inline Memory Module): A plug-in module of memory. You can add memory to your computer by plugging one or more DIMMs into the computer's memory expansion slots. Be sure to get the right kind of DIMM (or SIMM) for your computer.

DVD : (Digital Versatile Disk): Beyond CD-ROM - DVDs can store video movies and similar material. DVDs are the same size as CD-ROM disks. Most DVD players can also read CD-ROMs, but ordinary CD-ROM drives cannot read DVDs.

DRAM : (Dynamic RAM): RAM that is volatile - it loses its data when power is interrupted. A computer's main memory is typically dynamic RAM.

EDO : (Extended Data Out): Used for a computer's main memory, EDO RAM is a dynamic RAM that performs somewhat better than ordinary RAM.

Ethernet : The simplest and most commonly used network for connecting small computers. An Ethernet connection can run at 10, 100, or 1000 megabits per second.

Flash : A small, non-volatile memory. Non-volatile means that the memory keeps its data even when power to the computer is turned off. Some digital cameras use flash memory to store pictures. Not to be confused with ordinary camera flash, or a sudden realization.

G (giga): Short for 1,000,000,000 or 1,073,741,824. For network speeds, it means 1,000,000,000 - a gigabit Ethernet connection can send or receive 1,000,000,000 bits per second. For memory it means 1,073,741,824 - each gigabyte of memory is 1,073,741,824 bytes. Gigabyte is abbreviated GB.

GUI (Graphical User Interface): This refers to the "desktop" of your computer or the appearance of a windows-based application program.

IDE : (also EIDE - -Extended IDE): One or the two most common interfaces for hard disk drives (the other one is SCSI).

ISP (Internet Service Provider): The organisation through which your connection to the Internet is established. Home computers typically use a modem to connect to the ISP via ordinary phone lines or cable TV lines.

K (kilo): Short for 1000 or 1024. For modems it means 1000 - a 28.8K modem sends and receives 28,800 bits per second. For memory, it means 1024 - a 256K memory cache has 256K (262,144) bytes of storage. Kilobyte is abbreviated KB.

M (mega): Short for 1,000,000 or 1,048,576. For network speeds, it means 1,000,000 - a 100 megabit Ethernet connection can send or receive 100,000,000 bits per second. For memory it means 1,048,576 - each megabyte of memory is 1,048,576 bytes. Megabyte is abbreviated MB.

Mac : Short for Macintosh.

Modem : Short for modulator-demodulator. A device that connects a computer to an ordinary phone line, so that it can send and receive data.

Parallel Port : One of the external ports on a PC. It is typically used to connect a printer, or an external removable storage device.

PC : Short for Personal Computer. This usually means an "IBM-compatible" personal computer - one that uses an Intel processor or look-alike and a DOS or Windows operating system.

PCMCIA : (Personal Computer Memory Card International Association): The name given to the small credit-card size memory modules or peripheral devices that plug into PCMCIA slots on portable computers.

Peripherals : Devices that work with your computer - printers, scanners, cameras, microphones, speakers, keyboards, mice, game controllers, and so on.

RAM : (Random Access Memory): Any part of memory can be accessed at any time, as distinguished from disk or tape devices, in which memory locations are accessed sequentially. The main memory of a computer is dynamic RAM.

SCSI : (Small Computer Systems Interface): One of the two most common interfaces for hard disk drives (the other one is IDE). The SCSI disk interface is used extensively in Macintosh computers and occasionally in PCs.

SDRAM : (Synchronous Dynamic RAM): Used for a computer's main memory, SDRAM is a dynamic RAM that performs somewhat better than ordinary RAM.

Serial Port : One of the external ports on a PC. Most PCs have two external serial ports. These are typically used to connect a mouse or modem.

SIMM : (Single Inline Memory Module): A plug-in module of memory. You can add memory to your computer by plugging one or more SIMMs into the computer's memory expansion slots. Be sure to get the right kind of SIMM (or DIMM) for your computer.

SRAM : (Static RAM): RAM that is non-volatile. SRAM is much more expensive than dynamic RAM. Computers sometimes use small amounts of SRAM for specialised functions.

V.90 : A coming 56K modem standard that will replace X2 and Flex. The latter are two incompatible standards that currently coexist. If you have one of these modems and your ISP supports only the other, your 56K modem will typically connect at 28.8K, so you won't benefit from the higher speed capability. The V.90 standard will eventually be supported by almost all ISPs.

The preceding material was written by Ed Dalton. These are the opinions of the author, not the opinions of eBay, and therefore eBay does not validate the accuracy of or endorse these opinions.

A Brief History
Factors Influencing Value
Major Computer Categories
Choosing Computer Equipment
Tips for Finding and Buying
Tips for Listing and Selling
Caring for Your Computer Equipment
Insuring Your Computer Equipment
Glossary